bond energies

Question 1

During a reaction, enthalpy changes take place because bonds are being broken and formed
Energy (in the form of heat) is needed to overcome

Answer 1

attractive forces between atoms

Question 2

Bond breaking is therefore

Answer 2

endothermic

Energy (in the form of heat) is needed to overcome attractive forces between atoms

Question 3

Energy is released from the reaction to the surroundings (in the form of heat) when new bonds are formed
Bond forming is therefore

Answer 3

exothermic

Question 4

The sum of the energy in and energy out determines whether the reaction is overall

Answer 4

exothermic or endothermic

Question 5

If more energy is required to break bonds than energy is released when new bonds are formed, the reaction is

Answer 5

endothermic

Question 6

If more energy is released when new bonds are formed than energy is required to break bonds, the reaction is

Answer 6

exothermic

Question 7

In reality, only some bonds in the reactants are broken and then new ones are formed